Structural, magnetic and electrical properties of La0.67Pb0.33Mn1−xCoxO3 (0 ≤ x ≤ 0.3)

The structural, magnetic and electrical properties of La0.67Pb0.33Mn1−xCoxO3 (0 ≤ x ≤ 0.30) perovskites prepared by the sol–gel method were investigated. The rhombohedral distorted perovskite structure with space group R3¯c is observed in this series of materials while the average size and Co content are varied simultaneously. The Rietveld refinement of the structure shows that the substitution of Mn by Co in the Mn site changes the structure parameters such as the (Mn,Co)–O bond length and (Mn,Co)–O–(Mn,Co) angles. An increase in the (Mn,Co)–O bond length with increasing Co content leads to a decrease in the paramagnetic-ferromagnetic transition temperature TC and the metal-semiconductor transition temperature Tp.